Most of her career is academical (National Fund for Scientific Research) at the exception of five years at the Headquarters of the Belgian Gendarmerie for studying the spatial structure of road accidents. Since 1991, she has a permanent research position at the National Fund for Scientific Research where she now holds the title of “Research Director”; she conducts her researches in a multisciplinary research centre (C.O.R.E.) and has teaching activities at the Department of Geography of the U.C.L. For the period 2016-2019 she manages C.O.R.E. for the research activities (Research Director).

Isabelle Thomas is particularly interested in (1) modelling the location of human activities and more particularly the sensitivity of the models to their inputs, but also understanding the spatial structure of human activities and transportation fluxes, and (2) quantitative analysis for (urban) spatial data. Topics such as scale, m.a.u.p., autocorrelation, mapping procedures, multivariate modeling, big data, etc. are of particular interest. Application domains are mainly periurbanisation, road accident analysis, housing, employment, health, accessibility and socio-economic data, and the studied areas are limited to urban and periurban areas in Europe.